With the most frenzied bump watch in history set to begin, the announcement of Duchess Kate’s pregnancy (and her subsequent hospitalisation) throws a spotlight on a rare and debilitating condition known as hyperemesis gravidarum (HG).

Here, Una Rice, shares the story of her hellish experience with HG while pregnant with twins.

"My memories of the first half of my pregnancy are of being sick morning, noon and night. I started to be sick as early as four weeks - before I even knew I was pregnant. When my pregnancy was confirmed I did a big healthy food shop and spent a fortune - and then two days later went off everything. Even an apple would make me sick. But I thought this was normal pregnancy sickness which would all be over by 12 weeks.

"Nine weeks into my pregnancy the sickness took a more serious turn. The day started as usual - I got up, vomited, had a cup of tea, vomited again, had a yoghurt, more vomiting, some toast, vomiting, and so on. I began to get worried when it hadn't stopped by midday as it usually did - it just went on and on.

"By the next day I was dehydrated and vomiting blood, and my urine was the colour of coffee. My sense of smell also became heightened. I couldn't stand the smell of cooking and it got so bad that I had to sleep with a bottle of lemon-scented perfume to keep the smell of food away. I phoned my GP who seemed laid-back about it all; she just said not to worry, as it was just morning sickness.

Related: More than just morning sickness

"The constant vomiting went on for a couple more weeks, then subsided for a while. Thankfully I was able to eat a little - things like breadsticks and Nesquik milkshakes, which was bizarre as I absolutely hate milk. My main concern during this time was keeping down enough folic acid, so my husband Adrian added it to my milkshakes. He was very supportive - he would also spoon feed me things like chicken soup just to make sure I was getting some nutrition.

"When I was still being sick all day and night at around 12 weeks Adrian took me to hospital. They said I was very dehydrated and admitted me straight away. They put me on a drip, which was fantastic - it made such a difference to have fluids going into me. While I was there I had a scan which showed I was having twins. The sonographer turned the screen around so I could see two little heartbeats. I was delighted and it helped to know that this was part of the reason why I was so sick.

"I also accepted the hospital's offer of anti-emetic drugs. I hate taking any kind of drugs normally, even paracetamol, but this time I was so desperate for the sickness to stop, even just for a few days, that I relented and took them. Being sick for a few days is bad enough, but when it goes on for weeks it's awful. I felt so weak and tired all the time. I had no energy - constant vomiting takes its toll on you. And it wasn't as if I hadn't already tried every self-help remedy going - fresh ginger tea, acupressure wristbands and arrowroot biscuits to name a few.

"After I was discharged from hospital I discovered meditation. When I was feeling awful it helped to lie on the bed and focus on something pleasant - it was usually the only way to take my mind off the nausea.

"At around 20 weeks the sickness started to subside and I got my appetite back. I made up for lost time by eating really well. I was also scanned around this time and the sonographer told me the babies were fine and gaining weight. I used to pat my stomach every night saying 'come on babies - hang in there!'.

"The boys were born by caesarean at 38 weeks. They were healthy and I was relieved they were a good weight despite what I had been through. I was also pleased that by the end of the pregnancy, despite all the vomiting, my hair and teeth were fine. Maybe it's because I had a healthy diet before I got pregnant.

"If you have hyperemesis gravidarum, it's important to remain optimistic and to remember that at some stage it's going to end - and that you'll have a lovely baby to show for it. I'd go through it again and more for what I have now - two brilliant boys."

For more information about hyperemesis gravidarum, visit the Hyperemesis Education & Research HER Foundation at www.helpher.org

Did you suffer from HG or severe morning sickness? Please share your comments below.